Method for processing saponified sewage

Abstract

The present invention ptovides saponified sewage treating method, and the method is one mechanical speeded clarification plus horizontal screw centrifugal machine separation plus neutralization method. The method has the functions of smooth running, high economic property, high controllability and high separation effect.

Description

technical field [0001] The invention relates to a treatment method for saponified sewage, in particular to a treatment method for solid-liquid separation of lime dregs in saponified sewage produced in the production process of epichlorohydrin and propylene oxide. Background technique [0002] Saponification sewage is the alkali slag wastewater discharged from the saponification process, mainly containing CaCl 2 , Ca(OH) 2 , CaCO 3 , chloropropane, glycerin, trichloropropane, etc.; the average solid content is 0.63%; the normal water temperature is 85°C; the pH value is about 13. Due to the large amount of alkali slag, Ca 2+ and OH - , if discharged directly, it will cause the COD value and PH value of the sewage to exceed the standard seriously, causing pollution to the water body and the atmosphere. Therefore, it must be treated to remove the lime milk slag and organic residues and adjust the pH value before it can be discharged. [0003] The processing method of sapo...

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Problems solved by technology

[0006] (1) The natural sedimentation speed in the sedimentation tank is slow, the sedimentation effect is poor, a large amount of lime residue cannot be effectively precipitated and separated, and the content of suspended solids in the effluent of saponification water is at the lowest when it is 1000mg / L, Ca 2+ When the content is the lowest, there are still 9000mg / L

Going directly to the next link will have a great impact on the sludge cleaning cycle of its treatment facilities;

[0007] (2) The use of grab buckets to manually dig slag cannot meet the needs of continuous slag discharge of the device. During non-working hours, especially at night, due to excessive sediment, the sedimentation and separation capacity of the sedimentation tank is reduced, and the concentration of suspended solids in the discharged wastewater is high (the content of suspended solids in the effluent reaches 10000mg / L), the slag content is larger;

[0008] (3) The water content of the mud slag is more than 90%, which not only increases the transportation cost, but also causes secondary pollution to the environment after the burial because the water in the mud slag contains pollution sources such as organic matter;

[0009] (4) The acidity and alkalinity of sewage cannot be effectively controlled, and it can only be controlled within the range of pH 7-12

[0012] (1) No flocculant is used, and the settling effect is poor;

[0013] (2) The plate and frame filter press needs to be backwashed, and the operation cannot be continuous and automatic;

[0014] (3) The plate and frame filter press takes a lot of labor and is labor intensive

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